【摘要】 采用自主设计搭建的非均匀电场动态破乳聚结特性实验装置,首次在国内配套使用高频/高压脉冲交流电源和FBRM G600型聚焦光束反射仪,建立了W/O型乳化液中分散相水颗粒粒径分布的在线测试评价方法,进而系统研究了电场参数和流动参数对W/O型乳化液在非均匀电场作用下动态破乳聚结特性的影响规律。实验结果表明,对于所配制含水率为20%的W/O型乳化液,在电场强度为2.87 kV×cm^-1、电场频率为2 kHz、占空比为50%时,分散相水颗粒体积平均粒径（VMD）值较初始稳定状态的增长倍数达到最大值,为3.81倍;小粒径水颗粒（粒径小于10μm）数目较初始稳定状态减小至最小值,减少了62%;充分证明在非均匀电场下,合理电场参数的筛选对于乳化液破乳聚结具有重要意义。在实验流速范围内,VMD值增大倍数随着流速的增加先增大后减小,表明在确保足够停留时间的前提下,适度增加乳化液流速方能显著提升破乳聚结效率,因此合理流速的确定应当优先满足乳化液在电场中最短停留时间的要求。更多还原

【Abstract】 A dynamic demulsification apparatus with non-uniform electric field was designed and built, and the apparatus was equipped with high-frequency/high-voltage pulsed alternating current power supply and G600 Focused Beam Reflectance Measurement（FBRM）. An online evaluation method for size distribution measurement of water phase in water-in-oil emulsion using the designed apparatus was established, and effects of electric and flow parameters on dynamic demulsification and aggregation of water-in-oil emulsions under non-uniform high-frequency electric field were systematically investigated. The results show that when studied under conditions of electric field strength = 2.87 kV×cm^-1, frequency = 2 kHz and duty ratio = 50%, the volume mean diameter（VMD） of dispersed water-droplets within prepared water-in-oil emulsions（20% water） increases by 3.81 times as that of initial state. The number of small water particles（particle size < 10 μm） gets maximum decrease of 62%. These results demonstrate that selection of electric field parameters is critical for demulsification under non-uniform electric field. VMD increases first and then decreases with the increase of flow velocity within studied flow rate range, which indicates that emulsion flow rates can significantly improve electrostatic efficiency under sufficient residence time. Therefore, the required shortest residence time of emulsions within electric field should be satisfied in order to determine reasonable flow rates.更多还原